Circuit-interrupter.



F. W. HARRIS.

CIRCUIT INTERRUPTER. APPLICATION man lumi 1r. 19nd.

Patented Nov. 2, 1915.

WITN ESSES:

F. W. HARRIS. cmcun INTERRUPTER.

4 APPLICATION FILED IUNE I7. |910.

Patented Now/2.2, 1915.

2 SHEETS-SHEET 2.

I 1li s NORD W. HARRIS, OJE s ELECTRIC AND MN'UFACTURING CGMPANY, A CORPCRATION OF PENNSYLVANIA.

crncurrrnrnnnurrnn.

Specification of Letters Patent.

Patented Nov.. 2, 1915.

lApplication led .Tune 17, 1910. Serial No. 567,485.

To all whom t may concern.

Be it known that l FORD W. HARRIS, a citizen of the United tates, and a resident of Wilkinsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Circuit- Interrupters, of which the following is a specification.

My invention relatesto electric circuit interrupters of the oil-immersed type and-it has special reference to interrupters which are required to handle comparatively large amounts of current at relatively low voltages.

lThe object of my invention is to provide a device, of the character above indicated, that shall be simple and durable in construction and adapted to perform its functions e'ectively.

In service of the above mentioned character, circuit breakers are subjected to particularly severe operating conditions, land the heating of the breaker parts is a matter of serious difficulty. The circuit breaker of my invention is especially adapted to meet those requirements and to reduce excessive heating to a minimum, and it embodies means for securing intimate contact over the entire faces of the contact members, and for insuring proper alinement of said members. Means are employed to eliminate the heating eect of eddy currents in the heavy copper terminals and additional means are pro- -vided for overcoming the destructive action of the ares which are vformed when the circuit is interrupted.

In the accompanying drawings, Figure 1 is a view, partially in side elevation and partially in section, of a circuit interrupter constructed in accordance with my invention. F ig. 2 is an end View, partially in section,4 and Fig. 3 is a diagrammatic view showing the circuit connections and the relations of the contact members.

Referring to the drawings, a circuit interrupter 1 comprises a frame 2 secured, at one end, to an insulating slab or panel 3 and supported, at the other end, by a pipe standard 4. Secured to the frame 2, is an insulating slab or plate 5, to which are connected stationary contact terminals 6, 7, 8, 9, 1() and 11, arranged in pairs to coperate with a lurality of movable bridging contact members 12, 13 and 14. The stationary contact terminals are all alike and each of them is fastened to the insulatingplate 5 by means of bolts 18 and 19. Each of the terminals is grooved in such manner as to receive parallel copper straps 20, which it tightly into the grooves and are held in place by pins 21. The multi-strap conductors 20 extend through rectangular openings 22 in the insulating plate 5 to form the terminals of the interrupter to which the external circuit connections are made. By constructing the terminals in this manner, the eddy currents usually set up by heavy circuit currents are largely broken up and the consequent heating obviated.

The movable contact members 12, 13 and 14 are of like construction and are respectively adapted to engage the stationary contact terminals 6 to 11, inclusive, in pairs. Each movable member comprises a bridging member 23 and auxiliary arcing contact devices 24. The bridging member 23 is composed of strips of copper which are held together by means of curved clamping plates 26 and 27. Tubular member 30 of each arcing contact device may be integral with the outer clamping plate 27 and may serve as a guide for arcing tip 31 which ts loosely therein. The arcing tip 31 rests against a helical spring 35 which surrounds a rod 36, the latter forming an arcing tip extension to which a flexible copper shunt 37 is connected.

A contact plate 38 is secured to each main stationary contact terminal by means of a screw 39 and has its contact face' slightly inclined with reference to the direction of movement of the contact members, so that a slight rubbing action occurs as the contact surfaces come into engagement, thus insuring a perfect Contact.

The movable contact .members are pivotally suspended from rods 41 and 42 by means of pins 43 which are insulated from the current-carrying members of the interrupter by bushings 44. Rods 41 and 42 project through holes in the plate 5 and are provided with adjustable nuts 48 and 49, between which Vand a supporting member 45 are located helical springs 46 and 47 which surround the rods and carry the weight of the contact members. The springs 46 and 47 may be independently adjusted by means of the adjusting nuts 48 and 49, to distribute the pressure uniformly across the faces of the contact member, and simultaneous action The supporting member 45 is suspended,-

from a main lever 54, one end of which is pivotally supported by a stationary pin 55, and the other end of which is pivotally fastened to a yoke '52 having depending links 56 and 51 which are attached. to the mem-- ber The circuit interruptor is actuated by means of a compound operating lever 60, which is provided with an insulating handle and comprises outer members 62 and an inner member 63. One end of a link 64 is connected to thelever 54: at 68 and its other end is connected to the inner member 63 of the operating lever at 69. The inner member 63 of the operating lever is fulcrumed on a pin between the outer members 62 of said'lever. The construction of the inner member 63 is such that a toggle formed by it and the connecting link 64, is drawn nearly into dead center when the operating lever is in its lowest position. The movement of the inner member 63 is independent of the outer members 62, exce t as the said members are secured together by a'latch 73. The latch 73 is pivotally mounted at 74 between the members 62 and its lower portion forms a tripping lever 57 which is adapted to be struck by the hammer rod 92 of the movable core 91 of a tripping magnet 90, whenever said magnet is energized a predetermined amount. Pin 58 engages a spur 59 on the latch 73 and restricts movement of the latch in a counter clockwise direction. The handle 61 is provided with a recess to receive a rod 81 and a spring 80 which is interposedbetween a push button 82 on the rod, and the bottom of the recess.

A locking trigger 83, which is normallyadapted to engage a catch 86 on the operating handle`to.hold it in its set position, is pivoted at 84 on a bracket 88 and is maintained in engagement with the catch 86 by means of a spring 85 acting through a lever arm 89. To release the locking trigger 83 from the operating handle, the rod 81 is forced inward against the spring 80, by

means of the push button 82. In order to absorb the shock occasioned by the lsudden drop` of the breaker parts as the breaker opens, members and 96 are provided which rest against springs 97 andiI 98, respectively, and tend to relieve the jar' on the breaker mechanism.

The operating mechanism herein described', forms no part of my invention, except as it performs a necessary function in the operation of the device in question, and it may therefore be replaced by any' other suitable means for accomplishing the same' purpose.

rIhe breaker being closed, and the various parts occupying the positions shown in the drawings, the operation is `as follows: Assuming that thetripping magnet 90 is energized sufficiently to cause the hammer rod 92 of the movable core member 91 to engage the tripping lever 57 of the latch 73, the inner member 63 of the operating lever is released and the Weight of the breaker `parts, acting on the 'toggle formed by the connecting link 64 and the inner members 63 of the operating lever causes it to collapse, and the breaker opens. he operating lever member 63 'take by the dotted lines in ri sition of the operating handle 50 remains un- 'oiie the pochanged. The parts or the movable Contact members areso proporticned` that, breaking 'the circuit, the current-carrying brushes are allowed to 'separate from ne stationary contact terminals a considerable distance prior to the separation of the arcing tips and plates. The arc which is produced at the time of interruption is, therefore, restricted to the arcing tips and plates and the main contact surfaces remain in efhcient condition to insure perfect contact. To set the breaker, the push button 82 is forced against the spring 80 and the locking trigger 83 is released by the rod 81. The operating handle 60 may then be raised to its uppermost position, where the latch 73 engages the inner member 63 of the operating lever, after which the breaker may be set by lowering the handle, until the locking trigger 83 again engages the catch 86 and thus retains the breaker in the closedposition.

Whereas I have illustrated and described a specificcircuit interrupter, I desire it to be understood that variations or modifications of the structure may be made which dov not dier materially from the construction set forth, and I desire that only such limitations shall be imposed as are indicated in the appended claims.

I claim as my invention:

1. In a circuit interrupter, the combination with stationary contact members and movable contact members, of an operating mechanism therefor embodying a'single supporting'member and a plurality of yielding and adjustable means disposed above said supporting member for suspending said movable contact members therefrom and rosition Vindicated v Aizo intensa thereby equalizing the pressure on the contact members. t

2. A circuit interrupter comprising stationary contact terminals arranged in pairs, movable bridgingl contact members, and an operating mechanism therefor embodying a supporting member, laterally disposed pairs of suspending rods and springs associated therewith for equalizing the pressure on the contact surfaces of each bridging member.

3. 'A circuit nterrupter comprising a plurality of stationary contact members arranged in pairs, a plurality of movable bridging contact members adapted to cooperate therewith, an operating mechanism comprising a plurality of links, a single supporting member from which the bridging members are yieldingly suspended, and insulated pin connections about which the bridging members are severally free to swing.

4. In a circuit interrupter, the combination with stationary and movable contact members, of-an operating mechanism for said movable contact members embodying a single supporting member for said movable contact members, two suspending rods for each of said movable contact members which extend through holes in the supporting member, and individual sustaining springs for said rods which rest upon said supporting member.

5. In a circuit interrupter, the combination with stationary and movable contact members, of anoperating mechanism there-y rality of stationary contact terminals ari -ranged in pairs, a plurality of movable contact members yieldingly suspended from a common supporting member and adapted to coperate therewith, an operating mechanism for said supporting member and associated contact members and circuit terminals composed of a'plurality of copper straps secured in parallel grooves provided in the stationary contact terminals.

7. In a circuit interrupter, the combination with a plurality of pairs of stationary contact members, and -a plurality of movable contact members, of an operating mechanism for said movable members embodying suspending rods which are disposed in pairs laterally across each movable contact member, a supporting member for said rods and springs surrounding said rods.

ln testimony whereof, ll have hereunto subscribed my name this th day of June,

FORD W. HARRS. Witnesses Gr. E. S'roI/rz, B. B. Hines. 

